Apparatus for creating uniform streams in flow passages



D. W. TURNER July 14, 1964 5 Sheets-Sheet 1 Filed July 14, 1959 1 Z B Z a u Z V W y m f w w 5% f m b liv yaw :w

D. W. TURNER July 14, 1964 APPARATUS FOR CREATING UNIFORM STREAMS IN FLOW PASSAGES Filed July 14, 1959 3 Sheets-Sheet 2 firs/woe ,Dasse w'fleusg By Ms ArraeME aS? ,Hiems, Elsa-Ag, Russeu. .KEQM

D. W. TURNER July 14, 1964 APPARATUS FOR CREATING UNIFORM STREAMS IN FLOW PASSAGES Filed July 14, 1959 3 Sheets-Sheet 3 .ZZ'lvewraQ. ,DELBEE WMQNEQ,

,By #15 Arram/Egs,

United States Patent 3,141,000 APPARATUS FOR CREATING UNIFORM STREAMS IN FLOW PASSAGES Delber W. Turner, Houston, Tex., assignor to Petrolite Corporation, Wilmington, DeL, a corporation of Delaware Filed July 14, 1959, Ser. No. 826,982 8 Claims. or. 252-360) My invention relates to a method and apparatus for creating uniform streams in electric emulsion treaters and other equipment.

In such electric treaters as in other equipment it is often desirable to change a high-velocity liquid stream into a slow-moving stream filling and advancing substantially nonturbulently along a large passage with substantially laminar flow and with all of its filaments moving with substantially equal velocities in a cross sectional plane transverse to the flow direction. It is an object of the invention to provide a novel arrangement for creating such a uniform-flow stream in a short distance, measured in the flow direction.

If a large stream ofrliquid could be subdivided and discharged through an infinite number of orifices equally spaced in a transverse discharge plane of the large passage, a piston-like flow along the passage would result. Each time alesser number of orifices is visualized one faces the problem of turbulence and unequal filamentary flow in the resulting large stream. For example, it is logical to picture the streams from the orifices as flowing individually in the flow direction for a considerable distance before joining into a single stream having any semblance ofuniform flow. Actually such streams induce Whirlpools and turbulence as they come together if the streams jet from the orifices at high velocity. It is an object of the invention to join a plurality of streams into a single stream with a minimum of turbulence.

I have found that an obstruction of appropriate size spaced an appropriate distance from a respective smaller stream will sequentially spread and centrally contract the streams at positions respectively upstream and downstream from the obstruction. It is an object of the invention to divide a large liquid stream into a pattern of smaller streams discharging in the desired flow direction and to position obstructions in the paths of the respective smaller streams that will cause such spreading and control contraction thereof. A further object is to control the size of such obstructions and the spacings thereof relative to the orifices forming such smaller streams so as to produce a uniform flow in -a uniform-fiow plane beyond the obstructions. Another object. is to design the system to produce such uniform flow at a. plane spaced only a small distance from the discharge planea distance that is only a very small fraction of the width of .the flow passage. Specifically it is an object to produce such uniform flow with forward advancement as small as about 8" in a flow passage of several feet in width.

It is important to the invention that the smaller streams should themselves be moving in the desired flow direction. It is also desirable that each smaller stream be discharged into the flow passage while itself moving substantially nonturbulently. In these regards it is an object of the invention to employ nozzles for discharging the smaller streams and to orient them relative to a manifold so as to damp out turbulence induced'by the delivery of the liquid to the nozzle.

A further object is to employ restricted orifices for delivering the liquid to the respective nozzles from a manifold to establish a substantial pressure drop across each restricted orifice thus leading to a uniform division of the manifold stream to the nozzles fed thereby. Another object is to mount the nozzles off center with respect to such 3,141,3fi0 Patented July 14, 1964 restricted orifices in a manner to dampen the turbulence in the nozzle created by the restricted-orifice discharge thereinto and cause the flow at the outlet of each nozzle to be substantially parallel to the axis of the nozzle.

In the creating of such large streams in a flow passage of reasonably short length the manner of withdrawing the liquid at the exit end of the passage assumes importance. It is an object of the invention to withdraw such liquid through a plurality of orifices distributed throughout an exit plane spaced downstream from the aforesaid obstructions. It has been found that a plurality of obstructions upstream from such orifices will equalize the withdrawal and it is an object of the invention in one of its embodiments to employ discharge and exit orifices facing each other within a flow passage with obstructions in the intervening space traversing all the respective orifices but spaced therefrom such distances as to equalize distribution and pick up of liquid across discharge and exit crosssectional planes of the flow passage in which the discharge and exit orifices are respectively located.

It is also an object to interpose flow straightening members in the flow passage downstream from the obstructions of the discharge orifices, these serving to damp out any turbulence that might be induced by friction or other actions.

An example of where uniform flow is critical is in the resolution of oil-continuous dispersions by settling or with the aid of high-voltage unidirectional or alternating fields between interspaced sets of parallel electrodes. Such electrodes are mounted to form interelectrode treating spaces disposed side by side to occupy most or substantially all of the cross-sectional area of a flow passage in a treating or flow-straightening zone transverse to the axis of the passage. By use of the invention coalescing effectiveness is increased, particularly, in an upward fiow system, because the more uniform flow tends to increase the population density of the dispersed particles in a coalescing zone between the discharge and exit planes, leading to increased probability of coalescence whether or not an electric field is present in the coalescing zone or a part thereof. As the particles continue to coalesce they enlarge to such size that they drop through the stream to the bottom of the container. The invention will be illustrated in conjunction with flow straighteners which can themselves aid coalescence or which can be energized electrically in the event the aid of electric action is desired in coalescing and separating the phases of a mixture or dispersion.

Several embodiments of the invention are shown in the accompanying drawings in which:

FIG. 1 is a vertical sectional view of one embodiment of the invention incorporated in an upright container;

FIG. 2 is a horizontal sectional view of the flow straighteners or electrodes, taken along the line 22 of FIG. 1;

FIG. 3 is a horizontal sectional view taken along either of the lines 3-3 of FIG. 1 or the line 33 of FIG. 4;

FIG. 4 is an alternative embodiment, partially broken away, showing the invention incorporated in a horizontal container to establish a horizontal flow;

FIG. 5 is a vertical sectional view of an alternative embodiment showing the invention incorporated in a horizontal container to effect a vertical flow therein;

FIG. 6 is a horizontal sectional view taken along the line 6-6 of FIG. 5;

FIG. 7 is a fragmentary view illustrating certain principles of the invention and portions of the apparatus suitable thereto;

FIG. 8 is a further enlarged fragmentary view of a portion of one of the nozzles of FIG. 7; and

FIG. 9 is a sectional view taken along the line 9-9 of FIG. 8.

FIG. 1 shows an upright cylindrical container 10 providing a flow passage 11. The axis AA of the container 16 extends in the desired flow direction, here exemplified as upward. The container is ordinarily of a diameter of several feet when the invention is employed in the commercial processing of fluids. Various functions may be performed in the container during the flow of fluid therethrough but the apparatus of FIG. 1 is designed primarily to separate the constituents of dispersions, the heavier phase dropping to the bottom of the container 19 and being withdrawn through a valved pipe 13, the lighter fluid rising to the top of the container and being withdrawn through a valved pipe 14.

A suitably pressured fast-moving stream of liquid enters the container 19 through a pipe 16. To change this stream into a large slow-moving uniform-flow stream rising in the container 10 with all of its filaments moving forwardly at substantially equal velocity in a cross-sectional plane transverse to the fiow direction, I employ a distributor means 2%} in a lower portion of the container 10. As best shown in FIGS. 1, 3, 7, 8 and 9, this distributor means includes a network of pipes including two header pipes 21 having outer ends closed by caps 22 and inner ends connected to a T 23 communicating with a riser portion 24 of the pipe 16. A plurality of distributor pipes 25 extend from opposite sides of the header pipes 21 in aligned pairs. The distributor pipes of each pair are of equal length and provide closed ends terminating near the inner surface of the container 10. At equal intervals along its length, each distributor pipe 25 includes a plurality of restricted orifices 26 respectively feeding nozzles 28 having discharge orifices 29 facing in the desired direction of fiow, indicated by the arrow 30 of FIG. 1, each nozzle being welded to its distributor pipe as suggested by the weld 32 of FIG. 8.

The discharge orifices 29 are arranged in a uniform pattern in a discharge plane D-D transverse to the axis AA of the container 10. The pattern is such that each discharge orifice is substantially equally spaced from its closest neighboring orifices. In a preferred arrangement, the discharge orifices 29 are at the intersection of lines crossing at right angles in a checkerboard pattern. However, diagonal patterns can be employed if desired. The object is to distribute the discharge orifices 29 substantially throughout the discharge plane D-D so that the nozzles 28 form a pattern of smaller streams 36 issuing in the flow direction into the flow passage 11.

It is desirable that the smaller streams from the respective nozzles 28 should be discharged from the discharge orifices 29 while moving substantially nonturbulently. At the same time, it is desirable that each restricted orifice 26 be substantially smaller in cross section than the corresponding discharge orifice 29. Also it is desirable to orient each nozzle 28 relative to its restricted orifice 26 so as to damp out turbulence induced by the delivery of the liquid to the nozzle through the restricted orifice. In this latter respect it is desirable to displace the longitudinal axis BB of each nozzle in a direction toward the entrance portion of the distributor pipe 25 from the center of the corresponding restricted orifice 26, indicated by the center line or axis C--C of FIG. 8. As suggested in FIG. 7, the liquid in the distributor pipe 25 moves in the direction of the arrow 34 and enters the restricted orifice 26 at an angle. If the nozzle 23 is offset toward the oncoming stream, the downstream side of the nozzle 28 will be closer to the downstream side of the restricted orifice 26 and the side stream will enter the nozzle with less turbulence. There will be a turbulent zone 35 (FIG. 7) adjacent the upstream sides of the restricted orifice and nozzle but this turbulence is substantially damped out before the resulting small stream 36 issues from the discharge orifice 29. To secure this result it is desirable that the length of each nozzle 28 be larger than its diameter. Ratios of length to diameter greater than about 2:1 are desirable. Turbulence is further reduced by slightly beveling the exit side of the restricted orifice 26, as indicated by the numeral 37, and similarly beveling the edge forming the discharge orifice 29, as indicated by the numeral 38. The restricted orifices 26 are of sutficiently smaller size than the discharge orifices 29 to create substantial pressure drops across the former, insuring that substantially equal volumes of the liquid will be discharged from the nozzles 28 irrespective of their spacing relative to the header pipe 21 which supplies them.

Commonly, the area of each discharge orifice 2? is about double or more the area of the corresponding restricted orifice 26. Area ratios of about 1.5 to 3.0 will usually be satisfactory. In the specifically exemplified embodiment, employing restricted orifices 26 that are 1" in diameter and discharge orifices 29 that are 1.5 in diameter, the area ratio will be 2.25.

The offset between the axes B-B and CC need be only a small fraction of an inch. Typically, the offset may be about .07 to .1 times the diameter of the discharge orifice or about .2 to .3 times the difference in diameter between the restricted orifice and the discharge orifice. With the above-exemplified diameters of 1 for the restricted orifice and 1.5 for the discharge orifice, an upstream offset of about 4;" will greatly improve the action.

Without more, the small streams 36 would respectively remain as individual streams for a considerable distance and would join by turbulence that in many instances would bring portions of adjacent streams together with some degree of violence, causing further turbidity. It is desirable that the streams approach each other tangentially or quasi-asymptotically in a plane EE representing approximately the start of the uniform flow zone. By use of the obstructions to be described, each stream 36 will be spread at a position upstream from the obstruction 45 and centrally contracted at a position downstream from the obstruction 45 as generally suggested by the lines 42 of FIG. 7 to produce the desired uniform or piston-like fiow.

The obstructions 45 should correspond in number and peripheral shape to the discharge orifices 29 and should be mounted in an obstruction plane OO at positions respectively centered with respect to the streams 36. Each obstruction 45 is preferably connected to its corresponding nozzle 23 by a U-shaped member 48 such as a bent rod having arms 49 and 50 respectively welded to the nozzle 28 and the obstruction 45 and a bight 51 connecting the arms and spaced sidewardly from both the nozzle and the periphery of the obstruction. For best results, the bight is displaced sidewardly from the nozzle a distance at least equal to the diameter of the discharge orifice 29, being thus substantially removed from the stream spread by the obstruction 45.

The shape of the upstream and downstream sides of the obstruction 45 is not particularly critical. Either convex or flat surfaces can be employed. For example, the left-hand obstruction 45 illustrated in FIG. 7 is substantially egg-shaped while the right-hand obstruction is shown as a flat circular disc 54 to the upper side of which the leg 50 is welded. Either shape or a more spherical shape can be uniformly employed throughout the pattern but for purpose of simplicity and low cost the flat circular discs 54 are preferred, these being suggested in the drawings of the several embodiments.

The size of the obstructions in the plane OO and the spacing thereof from the discharge orifices 29 should be controlled to produce the desired uniform-flow pattern in the fiow passage 11. In this connection, the diameter of the obstruction, measured in the plane OO, should always be larger than the diameter of the corresponding discharge orifice 29, preferably about 1.2 to 2 times the diameter of the orifice. Likewise the distance between the obstruction 45 and the discharge orifice 29 for best results, measured between the obstruction plane 0-0 and the discharge plane D-D, should preferably be =3 somewhat greater than the diameter of the obstruction although distances substantially equal to the latter diameter can sometimes be used. It is preferable to make such obstruction-orifice distance about 1 to 3 times the diameter of the obstruction.

For large-throughput equipment in which the flow passage 11 is several feet in diameter, it is desirable to employ discharge orifices 29 of a diameter of about 1 to 3", obstructions of a diameter of about 1.2 to 6", with obstruction-orifice distances about 2.5 to 6". A ratio of orifice diameter to obstruction diameter to orifice-obstruction distance well suited to the practice of the invention may be in the neighborhood 1.5:2.5:3.5. Spacings of the discharge orifices 29 in the checkerboard pattern shown will be about 10 to in such large-throughput equipment, usually about 12 to 14", but much smaller spacings can be employed if desired. With spacings of about 12" and with the above-mentioned ratio of about 1.5 :2.5:3.5, the flow will become uniform in a distance of about 8" beyond the obstruction plane OO, i.e., the distance between the planes OO and EE of FIGS. 1 and 7 will be as small as about 8".

Friction, obstructions or other actions in the flow passage 11 beyond the uniform-flow plane E-E may disturb the uniform flow. If so it may be desirable to impose flow-straightening baffles 60 in a flow-straightening zone 61 of thC'fiOW passage 11, the baffles dividing this zone into a plurality of narrow open-ended side-by-side passages 62. As shown, the baffles 60 are made of thin sheet metal shaped as concentric cylindrical members assembled in suitably supported internesting sets 64 and 65 with the lower edges of the set 65 protruding below corresponding edges of the set 64. The open-ended passages 62 therebetween are of equal width and of a length, measured in the direction of flow, many times greater than such width, thus exerting a flow-straightening action on the liquid stream that is beneficial if the invention is employed for separating dispersions. If such dispersions are oil-continuous, coalescence and separation of the dispersed-phase material can often be accelerated by applying a potential difference between the baflles 60 of the two sets 64 and 65 to establish high-voltage electric fields in the passages 62.

To prolong the uniform-flow character of the stream to a point near the exit end of the container 10 it is desirable to withdraw the liquid from the container at a plurality of positions distributed throughout an exit or withdrawal plane WW. While various multi-orifice collection systems can be employed in this regard, a very desirable system will be a reversely positioned arrangement of pipes, nozzles and obstructions designed as mentioned above. In this connection, FIG. 1 shows a network of pipes including header pipes 21a, collector pipes a corresponding to the distributor pipes 25 previously mentioned, nozzles 253a and obstructions a formed of circular discs 54a. The liquid withdrawn through the various nozzles 28a flows through the header pipes 21a to a T 23a to which the pipe 14 is connected. The latter pipe continuously conducts from the container the liquid entering such a collection system. Substantially the same design considerations apply to the collection system as set forth above with respect to the distribution system or distributor means 20.

The invention is not limited to the formation of uniform-flow streams advancing in an upward direction. FIG. 4 shows a horizontal container 70 equipped with the distributor means 20 of FIG. 1 at one end, indicated by corresponding numbers. If the apparatus is used for the settling of one material from another during the uniform flow in the direction of the arrow 30, the other end of the container 70 may be equipped with valved pipes 72 and 73 communicating respectively with the upper and lower interior portions of the container. If desired, the pipe 72 may be connected to a collector system of the type suggested in FIG. 1.

Nor is the invention limited to flow parallel to the longitudinal axis of a container. FIGS. 5 and 6 show the invention applied to the problem of creating a large uniform-flow stream moving along an upward flow axis transverse to the main longitudinal axis of a horizontal cylindrical container 80. The incoming liquid must here be distributed over a larger area and the flow passage 31 is here not of uniform crossesectional area at all elevations or in all planes parallel to the discharge plane DD.

In this embodiment the pressured fast stream of liquid enters through a pipe 86 and is divided by laterals 87 to discharge centrally into two header pipes 121. Distributor pipes provide restricted orifices and nozzles 123 as previously described. U-shaped members 148 mount obstructions, shown as circular discs 154 respectively above the discharge orifices of the nozzles 128 as previously described. These discharge orifices are distributed uniformly in the discharge plane DD, preferably in the checkerboard pattern previously described, see FIG. 6.

Flow-straightening members 160, here internested sets 164 and of thin straight parallel plates, are disposed in a flow-straightening zone 161. The resulting openended narrow passages 162 compositely fill substantially all of that portion of the flow-straightening zone above the distributor system. As before, the sets 164 and 165 can be electrically energized if insulated from each other, thus establishing high-voltage electric fields in the passages 162.

The liquid of the uniform-flow stream reaching the top of the container 80 can be withdrawn from the upper interior thereof by any suitable exit or collection means, preferably by use of a multi-orifice system. As shown, this collection system is an inverted duplicate of the distributor system in the bottom of the container, the unified streams being discharged through a valved pipe 180.

The invention substantially increases the eifectiveness of the processing steps performed during the uniform flow of the liquid in the container. For example, in the separation of dispersions in an upright system as shown in FIG. 1, the container having a diameter of about 10 feet, a change from a conventional perforated-pipe distributor to the distributor means 20 of FIG. 1 made it possible to reduce the residual or unsettled dispersed material in the eflluent oil from .015% to .001% by volume. The nozzle spacing was 12", using restricted orifices of 1" diameter, discharge orifices of 1.5" diameter, circular discs of 2.5" diameter and disc-orifice spacings of 3.5". The flow rate per square foot in a horizontal plane of the flow passage near the flowstraightening member 60 was about 55 barrels per day. In a similar but smaller upright system a change from a conventional perforated-pipe distributor to the distributor means 20 of the invention permitted an increase in flow rate from to barrels per day per square foot while decreasing the residual dispersed material from about .0064 to about .0005% by volume. Horizontal vessels of the type of FIG. 5 equipped with the invention likewise give increased throughputs and reduced residual contents of dispersed phase material as compared with the same equipment employing conventional perforatedpipe distribution equipment.

Various changes can be made without departing from the spirit of the invention as defined in the appended claims.

I claim as my invention:

1. Apparatus for creating in a flow passage several feet in width having a flow axis parallel to the desired flow direction a uniform flow of liquid in which all segments of such flow move in said flow direction with substantially equal forward velocity measured in each of a plurality of transverse uniform-flow planes disposed progressively along said flow axis, said apparatus including: a large number of nozzles arranged in a uniform pattern in a discharge plane transverse to said axis and upstream from the first of said uniform-flow planes, said nozzles being equally spaced apart in said discharge plane a distance of about to inches, said nozzles having cylindrical nozzle passages with their axes parallel to said flow axis, each cylindrical nozzle passage being of a diameter of about 1 to 3 inches and of an axial length at least twice such diameter, each cylindrical nozzle passage terminating in a discharge orifice in said discharge plane; means for dividing a pressured fast-moving stream of the liquid among said nozzles to form a pattern of smaller streams issuing in said flow direction from said nozzles into said flow passage in said discharge plane; a fiat circular plate for each orifice and of a diameter about 1.2 to 2 times the diameter of each discharge orifice; and means for mounting the fiat circular plates in an obstruction plane transverse to said axis respectively concentric with the axis of said cylindrical passages and centered in the paths of flow of said small streams to spread the latter, the distance between each circular plate and its discharge orifice being about 1 to 3 times the diameter of such circular plate, the ratio of orifice diameter to plate diameter to plate-orifice-distance being substantially 1.5 22.5 :35, the spreading streams coming together adjacent the first of said uniform-flow planes to produce said uniform flow at and beyond such plane.

2. Apparatus for creating in a fiow passage having a flow axis parallel to the desired flow direction a uniform flow of liquid in which all segments of such flow move in said flow direction with substantially equal forward velocity measured in each of a plurality of uniform-low transverse planes disposed progressively along said flow axis, said apparatus including: a plurality of distributor pipes each having a plurality of restricted uniformly spaced orifices facing in said fiow direction; means for mounting said distributor pipes in said flow passage in parallel relation in a plane transverse to said axis with the orifices of all said distributor pipes uniformly spaced in a geometric pattern in said plane; a plurality of short cylindrical nozzles mounted on said distributor pipes at positions respectively surrounding said restricted orifices, said nozzles forming discharge orifices in a discharge plane transverse to said axis, the diameter of each discharge orifice being substantially the same as the internal diameter of its cylindrical nozzle and being larger than its corresponding restricted orifice; a plurality of obstructions respectively concentric with the axes of said cylindrical nozzles in an obstruction plane downstream from said discharge plane, said obstructions being circular in said obstruction plane and respectively of a diameter larger than said discharge orifices and spaced therefrom a distance greater than the diameter of the circular obstruction; and means for delivering the liquid of said stream to said distributor pipes.

3. Apparatus as defined in claim 2 in which each distributor pipe has an entrance end and a closed end with a plurality of said restricted orifices therebetween, the center of each such restricted orifice being displaced from the longitudinal axis of the corresponding cylindrical nozzle toward the closed end of such pipe to open eccentrically on the interior of such nozzle.

4. In a treater for separating dispersions of immiscible materials, an assembly for creating a fiow of the dispersion that is uniform at all points in a cross section of a large fiow passage of a minimum transverse dimension of at least several feet having an axis extending in the desired flow direction, said assembly including in combination: a network of distributor pipes having a plurality of restricted orifices each of smaller diameter than the internal diameter of its pipe, said restricted orifices being disposed in a geometric pattern extending substantially throughout the entire cross section of said flow passage in a discharge plane transverse to said axis, said orifices facing in said flow direction, there being a uniform, mutually equidistant distribution of said orifices in said pattern; means for supplying a pressured fastflowing stream of the dispersion to said network of distributor pipes; a corresponding plurality of cylindrical nozzles attached to said pipes at the positions of said restricted orifices and respectively surrounding same, said cylindrical nozzles having axes parallel to said flow direction and parallel to the central axes of said restricted orifices, said cylindrical nozzles respectively terminating in discharge orifices, said cylindrical nozzles being of an internal diameter larger than the restricted orifices respectively discharging thereinto to reduce the velocity of the dispersion stream from the corresponding restricted orifices before discharge into said flow passage from the corresponding discharge orifices, each nozzle being of substantially uniform internal cross-sectional area throughout its length including its discharge orifice and being of an axial length larger than its internal diameter; a corresponding plurality of obstructions having circular peripheries whose diameters exceed the internal diameters of the corresponding nozzles; and brackets for mounting the obstructions on the nozzles respectively beyond the discharge orifices of the nozzles and spaced therefrom a distance at least equal to the diameter of the obstruction with said circular peripheries concentric with the axes of the respective nozzles to spread the streams of dispersion flowing from said nozzles and converge the central portions thereof beyond said obstructions, the spacing of said nozzles in said pattern being such as to bring the spreading streams together beyond said obstructions to produce said uniform fiow of said dispersion.

5. A treater as defined in claim 4 in which said obstructions are flat circular discs transverse to and concentric with the axes of the respective nozzles, in which the circular periphery of each of said discs has a diameter about 1.2 to 2 times the internal diameter of the corresponding nozzle, in which each of said discs is spaced from its discharge orifices a distance equal to 1 to 3 times the diameter of the corresponding disc, and in which each of said brackets is a U-shaped bracket providing portions respectively attached to a corresponding nozzle and disc and a bight portion displaced laterally from the path of the stream from the corresponding nozzle,

6. Apparatus for creating in a fiow passage having a flow axis parallel to the desired flow direction a uniform fiow of liquid in which all segments of such flow move in said fiow direction with substantially equal forward velocity measured in each of a plurality of uniformflow transverse planes disposed progressively along said flow axis, said apparatus including: a plurality of nozzles equally spaced in a uniform geometrical pattern throughout a discharge plane transverse to said axis upstream from the first of said uniform-flow planes, each nozzle having a discharge orifice facing in said flow direction; means for dividing a pressured, fast-flowing stream of the liquid among said nozzles to form a pattern of smaller streams issuing in said flow direction from said nozzles into said flow passage in said discharge plane, said means for dividing the liquid among said nozzles including a plurality of distributor pipes providing restricted orifices spaced substantially in said uniform pattern and facing parallel to said desired fiow direction with their central axes respectively within said nozzles, said nozzles being carried by said distributor pipes, said discharge orifices being larger than said re stricted orifices and respectively communicating therewith; a corresponding plurality of circular obstructions; and means for mounting the obstructions respectively downstream of, spaced from and coaxial with said nozzles in the paths of said smaller streams to spread same upstream of the obstructions and substantially centrally contract the spread streams downstream of the obstructions, the distance between each obstruction and its dis- 9 charge orifice being greater than the diameter of its obstruction which in turn is greater than the diameter of such discharge orifice.

7. Apparatus as defined in claim 6 in which each nozzle is a hollow cylindrical member attached at one end to a corresponding distributor pipe and open at its other end, the open end of said cylindrical member forming the nozzle orifice, said member being of uniform internal diameter from end to end thereof, the axial length of the hollow cylindrical member being greater than its said internal diameter.

8. Apparatus as defined in claim 7 in which said means for dividing said liquid among said nozzles includes a header and a plurality of said distributor pipes connected thereto and extending therefrom, and in which each distributor pipe is provided with a closed end portion and an entrance portion at the junction of such distributor pipe with said header, a plurality of restricted orifices being located between said entrance portion and said closed end portion, and in which the center of each such restricted orifice is displaced from the longitudinal axis of the corresponding nozzle in a direction toward said closed end portion of such pipe, each such restricted orifice opening eccentrically on the interior of such corresponding nozzle.

References Cited in the file of this patent UNITED STATES PATENTS 1,401,176 Miller et a1. Dec. 27, 1921 2,093,444 Hubbard Sept. 21, 1937 2,320,059 Bailey May 25, 1943 2,663,687 Bailey Dec. 22, 1943 2,778,685 Umbricht Jan. 22, 1957 2,855,356 Stenzel Oct. 7, 1958 2,855,357 Stenzel Oct. 7, 1958 2,976,228 Waterman et al. Mar. 21, 1961 

1. APPARATUS FOR CREATING IN A FLOW PASSAGE SEVERAL FEET IN WIDTH HAVING A FLOW AXIS PARALLEL TO THE DESIRED FLOW DIRECTION A UNIFORM FLOW OF LIQUID IN WHICH ALL SEGMENTS OF SUCH FLOW MOVE IN SAID FLOW DIRECTION WITH SUBSTANTIALLY EQUAL FORWARD VELOCITY MEASURED IN EACH OF A PLURALITY OF TRANSVERSE UNIFORM-FLOW PLANES DISPOSED PROGRESSIVELY ALONG SAID FLOW AXIS, SAID APPARATUS INCLUDING: A LARGE NUMBER OF NOZZLES ARRANGED IN A UNIFORM PATTERN IN A DISCHARGE PLANE TRANSVERSE TO SAID AXIS AND UPSTREAM FROM THE FIRST OF SAID UNIFORM-FLOW PLANES, SAID NOZZLES BEING EQUALLY SPACED APART IN SAID DISCHARGE PLANE A DISTANCE OF ABOUT 10 TO 20 INCHES, SAID NOZZLES HAVING CYLINDRICAL NOZZLE PASSAGES WITH THEIR AXES PARALLEL TO SAID FLOW AXIS, EACH CYLINDRICAL NOZZLE PASSAGE BEING OF A DIAMETER OF ABOUT 1 TO 3 INCHES AND OF AN AXIAL LENGTH AT LEAST TWICE SUCH DIAMETER, EACH CYLINDRICAL NOZZLE PASSAGE TERMINATING IN A DISCHARGE ORIFICE IN SAID DISCHARGE PLANE; MEANS FOR DIVIDING A PRESSURED FAST-MOVING STREAM OF THE LIQUID AMONG SAID NOZZLES TO FORM A PATTERN OF SMALLER STREAMS ISSUING IN SAID FLOW DIRECTION FROM SAID NOZZLES INTO SAID FLOW PASSAGE IN SAID DISCHARGE PLANE; A FLAT CIRCULAR PLATE FOR EACH ORIFICE AND OF A DIAMETER ABOUT 1.2 TO 2 TIMES THE DIAMETER OF EACH DISCHARGE ORIFICE; AND MEANS FOR MOUNTING THE FLAT CIRCULAR PLATES IN AN OBSTRUCTION PLANE TRANSVERSE TO SAID AXIS RESPECTIVELY CONCENTRIC WITH THE AXIS OF SAID CYLINDRICAL PASSAGES AND CENTERED IN THE PATHS OF FLOW OF SAID SMALL STREAMS TO SPREAD THE LATTER, THE DISTANCE BETWEEN EACH CIRCULAR PLATE AND ITS DISCHARGE ORIFICE BEING ABOUT 1 TO 3 TIMES THE DIAMETER OF SUCH CIRCULAR PLATE, THE RATIO OF ORIFICE DIAMETER TO PLACE DIAMETER TO PLATE-ORIFICE-DISTANCE BEING SUBSTANTIALLY 1:5:2.5:3.5, THE SPREADING STREAMS COMING TOGETHER ADJACENT THE FIRST OF SAID UNIFORM-FLOW PLANES TO PRODUCE SAID UNIFORM FLOW AT AND BEYOND SUCH PLANE. 